
class Rectangle : Parallel {

    public Rectangle(){}
    public Rectangle(Side s1,Side s2,Side s3,Side s4) => (this.s1,this.s2,this.s3,this.s4) = (s1,s2,s3,s4); 
    
    public bool isRectangle() {
        if (this.isParallel()==true && s1.getK() == 0) {
            return true;
        }else
        {
            return false;
        }
    }
}